Scraping machine and allied structure

ABSTRACT

The present invention relates to vehicles which may be designed and used for scraping unwanted debris such as poultry droppings from a particular collector bed to a desired locale such as a conveyer trough. The vehicle of the invention, though proveded with a power plant such as an internal combustion engine, is nonetheless fluid-pressure driven, with its blade structure also preferably being actuated by fluid pressure. In a preferred form of the invention, a setting of the hydraulic drive, so as to predetermine the direction of travel of the vehicle, will simultaneously position the blade correctly for appropriate scraping or at appropriate neutral position. Only a slight adjustment is needed to convert the blade structure to scrape in an opposite direction. Appropriate steering means is provided to selectively brake opposite sides of the vehicle.

limited tates aterat Dyreng 51 Aug. 1, 1972 154] SCRAPING MACHINE AND ALLHED STRUCTURE [72] Inventor: Ray Morgan Dyreng, Manti, Utah [22] Filed: Jan. 25, 1971 [21] Appl. No.: 109,230

Related US. Application Data [62] Division of Ser. No. 802,128, Feb. 25, 1969,

Pat. No. 3,601,834.

[52] US. Cl. ..l5/93 B, 119/22, 172/801 [51] Int. Cl. ..E01h l/00 58 Field of Search ..15/93 B, 340, 4; 37/41, 42,

2,973,536 3/1961 Doyle ..l5/93 R Primary ExaminerLeon G. Machlin Attorney-M. Ralph Shaffer 5 7 ABSTRACT The present invention relates to vehicles which may be designed and used for scraping unwanted debris such as poultry droppings from a particular collector bed to a desired locale such as a conveyer trough. The vehicle of the invention, though proveded with a power plant such as an internal combustion engine, is nonetheless fluid-pressure driven, with its blade structure also preferably being actuated by fluid pressure. In a preferred form of the invention, a setting of the hydraulic drive, so as to pre-determine the direction of travel of the vehicle, will simultaneously position the blade correctly for appropriate scraping or at appropriate neutral position. Only a slight adjustment is needed to convert the blade structure to scrape in an opposite direction Appropriate steering means is provided to selectively brake opposite sides of the vehicle.

4 Claims, 13 Drawing Figures [56] References Cited UNITED STATES PATENTS 3,077,682 2/1963 Small ..172/4.5 2,920,753 l/1960 Wenger ..198/224 3,329,225 7/1967 Dunn ..37/41X INYENTOR.

RAY MORGAN DYRENG HlS ATTORNEY PATENTEUMJ I 9 3.680.166

sum 2 or 4 a 54v 4 I02 6;

xii RAY MORGAN DYRENG BL v.

HIS ATTORNEY PATENTEuam; 1 I972 3.680.166

sum 3 OF 4 INVENTOR.

RAY MORGAN DYRENG HIS ATTORNEY SCRAPING MACHINE AND'ALLIED STRUCTURE This is a division of the inventors prior application entitled, Scraping Machine and Allied Structure, Ser. number 802 128, filed Feb. 25, 1969 now US Pat. No. 3,601,834, issued Aug. 31, 1971.

The present invention relates to utility vehicles and, in one form thereof, to an improved vehicle for scraping debris from a desired area to another area such a conveyer trough, dump or the like.

The vehicle of the present invention is ideally suited for use in egg-producing plants. Efficient egg production depends upon poultry being housed in cages disposed in long rows within buildings, the cages being stepped so as to provide a completely free area underneath the same for poultry droppings. The latter conventionally fall on a floor or collection bed. In some types of prior constructions conveyer belts have been used immediately underneath the floor area for transporting droppings to a point exterior of the building. However, the droppings are moist and are highly acid, and this results in a rapid deterioration of conveyer belt material; further the droppings are difficult to remove because of their sticky, moist condition. Egg ranchers are well aware that it is desirable for droppings to accumulate for a sufficient depth. In such a condition droppings tend to have time to dry out and, hence, are much more easily removed and usable, as for fertilizer,

An additional object is to provide a vehicle whereby V by means of a single control, direction of travel and in bulk form. But the task of removal has heretofore been undesirable and tedious. Some prior attempts have been made in using automatic removal equipment; those in the inventors knowledge have proven unsatisfactory in one respect or another.

The present invention is believed to represent a unique departure and improvement in the field; in particular, the vehicle of the invention preferably takes the form of a four-wheel drive unit having a constant-speed internal combustion engine or other power plant. The power plant drives a variable-speed fluid motor that in turn supplies fluid pressure for driving the transmission of the vehicle in either of two directions, as well as affording hydraulic pressure for an operating cylinder provided for blade actuation ofthe vehicle. The equipment preferably is so arranged that the blade is automatically disposed in proper condition and the vehicle is moved in a proper direction upon the actuation of a single control. Thus, this control not only will position the blade proper, but will also select the desired direction of travel. Reorientation of the operating or actuating handle will simultaneously stop, or reverse, the vehicle as well as modify the placement of the blade structure in a desired manner. Single-lever means turn the vehicle by alternately braking each side. The operator station is, of course, disposed at the vehicle side.

A principal object of the invention is to provide an improved utility vehicle optionally including improved brake means and a side-mounted operator station.

A further object is to provide a vehicle having a I power plant of preferably constant speed character, the

same powering an appropriate fluid-pressure means for driving a transmission of the vehicle in any desired speed and direction.

An additional object is to provide a vehicle which, with the employment of a constant-speed power plant, is constructed for pressure-fluid drive of the transmission and of an operating scraper mechanism therewith.

speed, neutral position, and utility blade positioning may be accomplished.

An additional object is to provide a four-wheel drive scraper vehicle for farm or ranch use, the same incorporating a variable fluid-drive powered by a constantspeed power plant, and this with a single control to select both stopping, translation and scraper blade placement of the vehicle.

An additional object is to provide a scraper blade vehicle wherein the blade may be easily adjusted to scrape in either of two directions and, during the nonoperating portion of the cycle, to be stored automatically in neutral position or raised position during return travel translations of the vehicle.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further object and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIG. I is a side elevation of a utility vehicle incorporating the principles of the present invention.

FIG. 2 is a plan view of the structure seen in FIG. 1.

FIG. 2a is a fragmentary view taken along the line 2a2a in FIG. 2.

FIG. 3 is an enlarged, fragmentary elevation of the blade structure of the vehicle whereinthe same has been actuated downwardly to assume a scraping position.

FIG. 4 is a view similar to FIG. 3 but illustrates the operating cylinder of the construction as having been retracted, as to its piston rod, so as to return the blade to a neutral, non-scraping position.

FIG. 5 is a view similar to FIG. 3, but illustrating an alternate placement of a piston rod of the actuating cylinder relative to the blade structure, this in order to condition the blade to scrape in an opposite direction.

FIG. 6 is an end view of a poultry ranch building showing the manner in which the vehicle is employed.

FIG. 7 is a side elevation of the structure in FIG. 6, illustrating how successive cuttings of poultry droppings may be made to urge the same to a conveyer pit.

FIG. 8 is a schematic view of a major portion of the equipment seen in FIG. 2.

FIG. 9 is a schematic drawing of the braking structure of the vehicle, indicating the manner in which the vehicle may be turned either to the right or to the left.

FIG. 10 is a block diagram of a hydraulic system usable in the present invention wherein the same is disposed in a neutral position, that is, with the actuating handle position at a neutral point.

FIG. 11 is a view similar to FIG. 10, but illustrates the handle as being drawn back by the operator so as to condition the hydraulic system for one direction of travel of the vehicle and one type of blade placement.

FIG. 12 is a vehicle similar to the schematic diagrams of FIGS. 10 and l 1, but illustrates the hydraulic system as being in a condition reversed to that shown in FIG. 11, wherein the transmission is driven in an opposite direction and the hydraulic cylinder oppositely conditioned for scraper blade retrieval.

In FIGS. 1 and 2 vehicle includes a frame 11 having suitable journal structure for journaling the four wheels 12. As seen in FIG. 8, each of the wheels 12 include stub journal shafts 13 which are provided with keyed sprockets 14. The respective sprockets 14 are driven by endless sprocket chains 15, 16, 17, and 18 in the manner indicated. The sprocket chains 14-18 hence loop around, in an engaging manner, the respective sprockets 14 to couple the same with drive sprockets 19-22 in the manner shown in FIG. 8. These drive sprockets are keyed to output shafts 23 and 24. The latter are coupled through disc or drum brake units 25 and 26 to axles 27 and 28 within axle housings 29 and 30. Axle housings 29 and 30 are mounted by flexible bosses. 31 and 32 at other suitable conventional means to transmission housing 33. The shafts 27 and 28 are connected to conventional transmission T disposed within housing 33. The input end of transmission T is driven by a fluid motor 35, the latter including shaft 36 connected directly to the mechanical input connection of transmission 34.

FIG. 9 indicates a convenient steering mechanism. Rod 37 is connected either in a fixed or pivotal connection at 38 to the forward end 39 of actuating rod 40. Actuating rod 40 is pivoted by pin means 41 to boss 42 of frame structure 43. The frame structure 43 is fixed relative to the remainder of the vehicle. Mounted to frame structure 43 are a pair of brake cylinders 44 and 45, the latter including movable pistons 46 and 47. Pistons 46 and 47. include piston rods 48 and 49, which terminate in end abutment members 50 and 51, respectively. Lines 52 and 53 are hydraulic brake lines connected in the usual manner to the. conventional brake actuating mechanisms within respective brakes 25 and 26. The remaining lines 54 and 55 are connected to the brake fluid reservoir 56 and to portions of their respective brake cylinders onopposite sides of the respective pistons 46 and 47.

In operations, so far as the steering portion of the structure is concerned, when'the lever 51 is pulled toward the user in the direction A then the hydraulic fluid beneath piston 46 will be urged toward the braking mechanism of brake 25 so as gradually to set this brake. It is to be noted that the remaining braking cylinder 45 remains unaffected, so that the upper or right hand axle is free to rotate the upper wheels of FIG. 2. Thus, the vehicle may be turned slightly to the left if this is desired. In a corresponding manner the rod 37 in FIG. 9 may be urged upwardly so at this time to urge piston rod 49 upwardly. The same urges the hydraulic breaking fluid upwardly with respect to line 53 so as to set the brake of the upper rear wheel 12 (and likewise brake the remaining upper wheel via the interconnecting sprocket chains) in FIG. 2, leaving the lower wheels to be operatively driven.

In the preferred'form of the invention the vehicle is a four-wheel drive vehicle. This is to be noted in connection in the employment of four sprocket chains 15-18. It is noted thus that a braking of one wheel as disposed at the upper right of. FIGS. 2 and 8 will likewise produce a braking of its companion wheel 14, such as that shown at the upper left-hand side of these two figures. This-is because the single brake 26 controls the braking action of the two wheels on the same side of the vehicle. For convenience, sprocket chain cover panels 59 and 60 may be disposed on opposite sides of the frame to cover and hence protect the sprocket chains, the sprockets and the journaling means used.

Mounted to the frame of the vehicle is preferably an internal combustion engine 61 as seen in FIG. 2. Coupled to engine 61 is a fluid pump 62 having a pressure line 63 and a return line 64. Return line 64 is directly connected to port 65 of reservoir 66.

Pressure line 63 is hence connected to port No. l of control valve 67. Port No. 1 is hence the pressure port relative to the valve. Valve 67 is controlled by a handle 68, the latter being pivotally connected to fixed boss 69 and having its lower end pinned at 70 to the extension 71 of the valve spool 72. Multiple port valve 67 is a conventional valve, such as No. 14301 of Husaw Mfg. Co., and having sufficient lands, bypass recesses and ports to accommodate the internal flow patterns illustrated in FIGS. 8, 9, and 10. As to plumbing, conduit 63 interconnects pump 62 with port No. 1 of valve 67.

Conduit 74 and 75 respectively connect to fluid motor 34 and port No. 4 of valve 67, and their juncture comprises a tee-connection which receives and connects conduit 76. The latter is connected to conduit 77 leading to the right side of operating cylinder 78. A valve 79 is preferably manually controlled and interconnects conduit 76 and 77. The remaining side of cylinder 78 is connected vto conduit 80 which in turn connects through valve 81 to conduit 82, the latter connecting to tee junction 83. Junction 83 is formed between conduit 84 and 85, the former connecting to port No. 2 of valve 67 and the latter connecting to fluid motor 34. Conduit 86 interconnects port No. 3 of the valve 67 to filter 87.

The latter is connected by conduit 88 to reservoir 66. Handle 68 is shown in neutral position in FIG. 10 as is indicated by the letter N. Accordingly, the path through the valve is indicated by dotted line 89 such that when pump 62 is driven by the internal combustion in engine 61, port No. l or valve 67 becomes a pressure port (and remains so throughout the operation of the equipment); however, owing to this condition of the valve spool 72,the pressure hydraulic fluid takes the path 89 directly to port No. 3 and proceeds through filter 87 back to reservoir 66 .which supplies the pump 62. Accordingly, this is a closed circuit such that the remainder of the valve and the conduit connected thereto and equipment associated therewith are inoperative.

Note is now made that conduit 90 interconnects valve port No. 5, see FIGS. 9 and 10, to reservoir 66. This is a direct circuit path and need not proceed through filter 87. Accordingly, when the handle is disposed out of neutral position (which will be hereinafter described) then the circuit path including conduit 86, 88 and filter 87 becomes inoperative. Note is to be made in connectionwwith the neutral position see FIG. 8, that when handle68 is in neutral position the pump pressure path assumes path 89 through the valve back to the reservoir via filter 87. Hence, no work is done by the circuit; thus, as to operating cylinder 78 (having piston 78) no fluid pressure will exist on either side of the piston. Therefore, when in neutral position the scraper blade, hereinafter described, remains in its then pre-determined condition.

At this point it is well to note that shut-off valves 81 and 79, though not strictly necessary, are highly useful in removing the operation of the scraping blade structure from the hydraulic condition of the system. Hence, when the machine is in neutral valves 79 and 81 may be turned ofi and the blade raised to a desired position. Thereafter, the vehicle can be run either to the right or to the left without chancing automatic blade operation.

Reference is now made to FIGS. 3 and 4 wherein it is seen that the operating cylinder 78 includes a piston rod 91 connected to piston 78', see FIG. The end of piston rod 91 preferably includes a pinned clevis connection 92 such that the pin may be inserted in a respective aperture A or B. When the blade BL is to be set in a condition as shown either in FIG. 3 or in FIG. 4, then the B" aperture of the blade structure is employed. Note is made that the blade BL preferably includes a curved blade back 92 integral with congruous, forwardly oriented sides 93. The latter is pivoted 94 by suitable pins 95 to the frame structure of the vehicle. Where piston rod 91 of FIG. 3 is extended, then the blade is in condition to scrape or urge poultry droppings in a direction to the right. This condition is shown in FIG. 3. When, however, the piston rod 91 is withdrawn as shown in FIG. 4, then the blade assumes a neutral position as indicated in FIG. 4.

The neutral condition has been described relative to FIG. 10. In FIG. 11 flow paths 96 and 97 are established in the valve upon the translation of the valve spool through the movement rearwardly of handle 68, see FIG. 9. In such a valve condition the pressure port No. l feeds hydraulic fluid in the direction 96 through the valve to port No. 2. Thus, the fluid proceeds outwardly to drive fluid motor 34 and, hence, transmission T in the manner such as to move the vehicle in a direction to the right. Line 85 is hence a pressure line, and where the valve 87 is open, the pressure fluid is automatically applied to the rear face of piston 78', thus moving the piston and its piston rod downwardly in a direction to the right so as to extend piston rod 91 and hence bring the blade in the piston shown in FIG. 3. Note is to be made that a return line for fluid motor 34 is through line 74 and port No. 4, through the valve along path 97 to port No. 5, and thence back to the reservoir via return line 90.

When the vehicle has traveled to the right sufficiently, then it is necessary then merely to return the handle 68 back to the neutral position indicated in FIG. 8. At this juncture fluid ceases to flow through the fluid motor, hence stopping the driving of transmission T. The vehicle stops. However, the blade will remain in its scraping position. Moreover, when the vehicle is moved in a counter direction, as by when the handle 68 is urged forwardly as shown in FIG. 10, then the blade assumes its neutral or raised position illustrated in FIG. 4. Note that in the condition shown in FIG. 10 the direction of fluid flow through the fluid motor 34 is reversed, and the circuit path completed via valve paths 98 and 99, respectively connecting ports No. l and No. 4 and ports No. 2 and No. 5. In such event then lines 74 and 75 become the pressure lines operating fluid motor 34. Line 76, in being teed into this pressure line combination, becomes a pressure line for operating cylinder 78. Fluid pressure hence returns the piston 78 and its piston rod in a rearwardly direction so as to achieve the withdrawal condition seen in FIG. 4.

It is seen in FIG. 5 that the scraping function of the machine may be reversed simply by selecting another pin aperture for actuating cylinder 78. In FIG. 5, side aperture A of the blade structure now received the clevis connection and pin 62. Hence, the vehicle is now adapted to scrape in a direction to the left, see FIG. 7, with a return trip of the vehicle being automatically accompanied by a lifting of the blade structure to neutral position in a manner similar to that shown in FIG. 4.

When the blade is in the condition shown in FIG. 5, then it will be seen relative to FIG. 7 that successive cuttings of droppings may be urged toward trough 101. In this regard, it is desirable that the entire poultry operation be disposed in a single long building having a long concrete floor 102 interrupted by lateral troughs 101. Suitable concrete structures are supplied 'as a bridge or roadway for the vehicle across the troughs so that there is an uninterrupted travel bed for the vehicle. In such event the troughs 101 will be disposed underneath these roadways provided for the wheels. The troughs will be uncovered, however, in the scraping area so that successive cuttings may be deposited into troughs 101. These will be provided with conventional conveyer apparatus 103 consisting of elongate endless drive belts mounted upon suitable rollers and driven by motor means in a conventional manner.

It is desirable that droppings be allowed to accumulate to a substantial depth, this in order that the droppings may be allowed to dry out, at least a major portion thereof. Hence, and because of the opportunity for the cuttings to dry out, they are easily transported to the troughs, will not tend to stick unduly to the conveyer belt structure, and may be packed in bulk as fertilizer.

In FIG. 7 the vehicle will first take cuttings nearest the trough and then be displaced successively more to the right so as to take subsequent cuttings. Trackway' bridges B may be provided for the wheels on opposite sides of the dropping bed C, see FIG. 6. Rails D and E are provided to serve as travel-limit abutments for wheel travel.

Optimum utilization of the equipment is made when the poultry is arranged in long step rows in a manner similar to that shown in FIG. 6. Note is to be made that there is an uninterrupted area for droppings upon the dropping floor C. If desired, a suitable cover may be disposed over the machine as the same is made to travel underneath the cages E.

As has heretofore been noted, slight steering adjustments may be made by apparatus shown in FIG. 9. Additionally when the vehicle is removed from the poultry enclosure, then right and left adjustments are easily made by braking either the right side or the left side of the vehicle by the handle 37.

A suitable gauge board 104 may be bolted to the frame and supply usual choke and fuel indicators for internal combustion engine 61. The lines leading to the engine and into the fuel tanks and battery are not specifically delineated, for convenience of illustration. These will all be conventional.

While it is possible to have a single return line to reservoir 66, it is desirable that during the idling portion of the cycle filter 87 be used in the return line to reservoir 66. Such is not required during operation of a vehicle in either right or left operating direction, in

nals 11'. The latter journal a blade structure BL which is employed forscraping poultry droppings from the floor of an egg'producing building. The vehicle is advantageously a four-wheel drive vehicle which is adapted easily to move in either direction, and this without disturbing the constant-speed running condition of the internal combustion engine of the vehicle. Of course, an electrically driven engine might equally serve. Thus, the constant running power plant or engine used is employed to drive a pump, the latter actuating a fluid motor which in turn drives the transmission and hence the wheels of the vehicle. Instant stopping and starting can be achieved and the transmission T may be driven either slowly or more rapidly, this depending upon the'displacement of the actuating handle 68 and the metering of the ports of control valve 67. Note is made that the fluid motor canbe stopped, started and metered without interrupting the constant specd of revolvement of the internal combustion engine 62. This increases the useful life of the internal combustion engine and avoids clutches, gear boxes and the like. Note is to be made that selection of the direction of travel of the vehicle automatically causes a correct positioning of the blade. If desired, appropriate limit stops means S and 8' may be secured to the side of the frame of the vehicle and to the blade to pre-determine the distance of blade descent. This may be desirable where it is deemed appropriate to raise the scraping edge of the blade slightly above the pavement at blade operation condition. The limit-stop arrangement may be disposed on one or both sides of the blade structure, as desired and if needed.

Again, the blade is disposed in either'a neutral or raised condition, or in a scraping condition; the direction of scraping is arranged by pre-selection of a selected pivot aperture relative to the piston rod extremity of the actuating cylinder. For convenience the actuating cylinder should be trunnioned as at F to the frame 11 of the vehicle. Accordingly, as the one blade setting (FIGS. 3 and 4) pulling back of the operating handle will cause the vehicle to advance to the right and the blade to descend in a manner seen in FIG. 3.

The vehicle is stopped in its motion to the right upon the returnof handle 68 back to neutral position as shown in FIG. 8. When the travel of the vehicle is reversed, as is produced through the circuit configuration as shown in FIG. 10, then the blade isvraised to neutral position as seen in FIG. 4. Thus, the blade is raised while the vehicle travels to take a subsequent cut of material, i.e. poultry droppings, to subsequently scrape or urgethese toward the trough 101 in FIG. 7.

While the pressure fluid system shown has been illus trated as a hydraulic system, it will be understood that a pneumatic system may be employed equally as well. In such an event the reservoir and fluid pump will comprise an accumulator compressor construction of conventional design.

In FIG. 1 it is seen that the operator station 0 is secured to a respective side of the vehicle. This permits,

convenient Fse of the machine by the operator while the frame 0 the vehicle 18 moved underneath the long rows of stepped poultry cages. See FIG. 6.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects.

I claim:

1. In combination, a vehicle having a frame, plural wheels supporting said frame, a power plant mounted to said frame, a transmission for driving said vehicle, fluid motor means for driving said transmission, means intercoupling said power plant with said fluid motor means for converting the output power of said power plant to fluid drive power .for said fluid motor means, and control means coupled to said power converting means for selectively starting, stopping, and reversing the actuation of said fluid motor means so as to selec tively start, stop, and reverse said vehicle, and wherein said vehicle includes a scraper blade movably connected to said frame, cylinder means coupled to and between said frame and said scraper blade for selectively, alternately positioning said scraper blade in operative and raised positions, and means for oppositely operating said cylinder means to so alternately position said scraper blade.

2. Structure according to claim 1 wherein said operating means comprise pressure fluid lines coupled to said power converting means, said control means being constructed and arranged to correlate automatically the position of said blade means in accordance with the travel direction of said vehicle, thereby positioning said blade means to scrape during forward vehicle travel and to be elevated to non-scrapeposition during reverse vehicle travel.

3. Structure according to claim 2 wherein said fluid lines each include selectively operable shut-off valve means.

4. In the combination of a vehicle, a scraping blade transversely pivoted to said vehicle, and means for rotationally displacing said scraping blade in to and out of mutually reversed scraping positions, an improvement wherein said scraping blade has forwardlydirected side portions for preventing lateral spillage and a back blade portion having upper and lower scraping edges and disposed at a normal position with respect to the forward direction of vehicle travel, said back blade portion extending between and being connected to said side portions, said side portions being pivoted to said vehicle, and said back blade portion being constructed and dimensioned such that both of said scraping edges may be positioned, selectively, proximate a given ground plane to effect a scraping function. 

1. In combination, a vehicle having a frame, plural wheels supporting said frame, a power plant mounted to said frame, a transmission for driving said vehicle, fluid motor means for driving said transmission, means intercoupling said power plant with said fluid motor means for converting the output power of said power plant to fluid drive power for said fluid motor means, and control means coupled to said power converting means for selectively starting, stopping, and reversing the actuation of said fluid motor means so as to selectively start, stop, and reverse said vehicle, and wherein said vehicle includes a scraper blade movably connected to said frame, cylinder means coupled to and between said frame and said scraper blade for selectively, alternately positioning said scraper blade in operative and raised positions, and means for oppositely operating said cylinder means to so alternately position said scraper blade.
 2. Structure according to claim 1 wherein said operating means comprise pressure fluid lines coupled to said power converting means, said control means being constructed and arranged to correlate automatically the position of said blade means in accordance with the travel direction of said vehicle, thereby positioning said blade means to scrape during forward vehicle travel and to be elevated to non-scrape position during reverse vehicle travel.
 3. Structure according to claim 2 wherein said fluid lines each include selectively operable shut-off valve means.
 4. In the combination of a vehicle, a scraping blade transversely pivoted to said vehicle, and means for rotationally displacing said scraping blade in to and out of mutually reversed scraping positions, an improvement wherein said scraping blade has forwardly-directed side portions for preventing lateral spillage and a back blade portion having upper and lower scraping edges and disposed at a normal position with respect to the forward direction of vehicle travel, said back blade portion extending between and being connected to said side portions, said side portions being pivoted to said vehicle, and said back blade portion being constructed and dimensioned such that boTh of said scraping edges may be positioned, selectively, proximate a given ground plane to effect a scraping function. 